Testing equality of variances in the analysis of repeated measurements

The problem of comparing the precisions of two instruments using repeated measurements can be cast as an extension of the Pitman-Morgan problem of testing equality of variances of a bivariate normal distribution. Hawkins (1981) decomposes the hypothesis of equal variances in this model into two subhypotheses for which simple tests exist. For the overall hypothesis he proposes to combine the tests of the subhypotheses using Fisher's method and empirically compares the component tests and their combination with the likelihood ratio test. In this paper an attempt is made to resolve some discrepancies and puzzling conclusions in Hawkins's study and to propose simple modifications.
The new tests are compared to the tests discussed by Hawkins and to each other both in terms of the finite sample power (estimated by Monte Carlo simulation) and theoretically in terms of asymptotic relative efficiencies.     

Government wage differentials

This paper shows that public sector wages usually exceed private but the size and composition of the differentials depend on sex and level of government. Using a technique derived from the literature on sex discrimination, these differentials are decomposed into a portion attributable to differences in productivity between the two types of workers and a portion ascribed to economic rent. This rent results from public workers' relatively greater political influence in the government wage-setting process and a systematic upward bias in public wages imparted by present government pay policy.     

MSE-improvement of the least squares estimator by dropping variables

It is well known that dropping variables in regression analysis decreases the variance of the least squares (LS) estimator of the remaining parameters. However, after elimination estimates of these parameters are biased, if the full model is correct. In his recent paper, Boscher (1991) showed that the LS-estimator in the special case of a mean shift model (cf. Cook and Weisberg, 1982) which assumes no “outliers” can be considered in the framework of a linear regression model where some variables are deleted. He derived conditions under which this estimator outperforms the LS-estimator of the full model in terms of the mean squared error (MSE)-matrix criterion. We demonstrate that this approach can be extended to the general set-up of dropping variables. Necessary and sufficient conditions for the MSE-matrix superiority of the LS-estimator in the reduced model over that in the full model are derived. We also provide a uniformly most powerful F-statistic for testing the MSE-improvement.     

Bridges over contested terrain: Exploring the radical account of the employment relationship

Richard Edwards' account of the transformation of the employment relationship in the twentieth century is used as a vehicle for integrating the radical analysis into the more conventional treatment. Most non-radical analyses rely on idiosyncratic skills to explain the existence of job security and other features of the modern employment relationship. Here an alternative explanation is proposed and some of its implications are explored.     

Means of livelihood of city populations: a livelihood classification of the cities in India

Indian censuses provide useful data on livelihood. These data give a picture of the distribution of population deriving their living from different economic activities. According to the 1951 census, 73 cities in the country had a population over 1 lakh. These cities were, more or less, evenly distributed in the different States of the Union. Of the populations in these cities combined, nearly 40% derived its livelihood from the services and miscellaneous sources, approximately 1/4 from production other than cultivation, 1/4 from commerce, and the remaining few from transport and agriculture. These averages were fairly similar for large and small cities. Of the 32 largest cities which showed predominance of their population in 1 or more livelihood, there were about 10 in industrial-manufacturing, 6 in commerce, 9 in transport, and 10 in services. 2 of the 3 port cities, Bombay and Madras, were broad-based in employment while Calcutta was predominant in commerce. There was little uniformity in the livelihood patterns of capital cities.     

Dynamic effects of externalities,optimal saving and economic growth

Conclusion Recognizing the fact that provision of mixed public goods can result in both consumption externalities of the Samuelsonian variety as well as production externalities we set out to extend the earlier results of Rao and Kalpagam (1977) on the effect of public goods on economic growth. In so doing, we considered three standard specifications of production externalities and enlarged the concept of consumption displacement. Our basic conclusion is that the results of our earlier paper remain valid under the more general conditions set out in this paper.     

The growth of shiftwork in the British food,drink and tobacco industries

The authors develop and estimate an econometric model of shiftworking for male, manual employees in the food, drink and tobacco industries. In the demand equations TSLS techniques are used to take account of simultaneity in the determination of shiftworking, capital intensity and plant size. Market demand variables are also incorporated in the model to allow for the distinction between ex ante and ex post decisions to work shifts. A demand variable is also incorporated in the supply equations. The results confirm the diverse economic characteristics of these industries, suggesting that inter-industry studies may conceal a considerable degree of variation at MLH level.